There is a solution that you can apply until Apple releases a fix.
MacRumors reported the news that a text message is being used to block Apple devices including iPhones, iPads, Macs, and Apple Watch.
The message includes an Italian flag emoji and characters in the Sindhi language, which causes the system to shut down immediately when the notification with the message is displayed. So it is advisable to disable notifications for new messages if you want to prevent this problem.
It should be recalled that as early as 2018 Apple had to deal with a similar problem, releasing a software update shortly afterward to solve the problem.